JP3580917B2 - Fuel cell - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell having a solid polymer electrolyte membrane sandwiched between an anode and a cathode.
[0002]
[Prior art]
In a solid polymer electrolyte membrane fuel cell, a fuel cell structure (unit cell) comprising an electrolyte comprising a polymer ion exchange membrane and a catalyst electrode and a porous carbon electrode disposed on both sides of the electrolyte is sandwiched by separators. And a plurality of such layers are stacked.
[0003]
In this type of fuel cell, hydrogen supplied to the anode electrode is hydrogen-ionized on the catalyst electrode, and moves to the cathode electrode side via a moderately humidified electrolyte. The electrons generated during that time are taken out to an external circuit and used as DC electric energy. Since an oxidizing gas, for example, oxygen gas or air is supplied to the cathode electrode, the hydrogen ions, the electrons, and oxygen react at the cathode electrode to generate water.
[0004]
By the way, in this type of fuel cell, for example, as shown in FIG. 11, fuel cell structures 2 and separators 4 are alternately stacked, and a power generation function unit (electrode unit) of the fuel cell structure 2 A structure is known in which cooling water is supplied to 2a in parallel with the flow direction of a fuel gas (for example, hydrogen gas) and an oxidizing gas (for example, oxygen gas).
[0005]
[Problems to be solved by the invention]
However, in the above structure, since the cooling water flows in the vertical direction of the power generation function unit 2a, a relatively large temperature difference occurs between the central portion of the power generation function unit 2a and both sides of the power generation function unit 2a due to heat dissipation. . As a result, water condensed and condensed on both sides of the power generation function unit 2a due to a temperature drop, and a portion of the power generation function unit 2a that does not operate is generated. Moreover, in the power generation function unit 2a, a part whose performance is deteriorated due to low temperature is likely to occur. As a result, a problem has been pointed out that the effective operating area and performance of the power generation function unit 2a are significantly reduced.
[0006]
The present invention solves this kind of problem, and can prevent a partial temperature difference from occurring in a fuel cell structure with a simple configuration, and can secure an effective working area and performance. It is intended to provide a battery.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention circulates a cooling medium used for cooling the power generation function of the fuel cell structure along the outside of the power generation function. Therefore, the cooling medium whose temperature has been increased by the heat exchange performed by the power generation function unit flows outside the power generation function unit. Thereby, the temperature difference between the central portion of the power generation function portion and the outer end portion of the power generation function portion is reduced, and dew condensation can be prevented, so that the effective operation area and performance of the power generation function portion can be improved. Can be
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
As shown in FIGS. 1 and 2, the fuel cell 10 according to the present embodiment is configured by stacking a large number of fuel cells (fuel cell structures) 20 in a horizontal direction. The fuel cell 20 includes a power generation function unit 28 including an anode 26 and a cathode 24 with a solid polymer electrolyte membrane 22 interposed therebetween. The configuration of the power generation function unit 28 is described in detail in, for example, International Publication No. WO09-15377, which is incorporated in the present invention. In this case, as shown in FIG. 2, the solid polymer electrolyte membrane 22, the anode-side electrode 26, and the cathode-side electrode 24 are separated from each other, but they may be integrated.
[0009]
As shown in FIG. 3, on the upper side of the electrolyte membrane 22, an oval hole 22a for passing a fuel gas such as hydrogen in one direction and a hole 22b for passing a cooling water are provided. And a hole 22c for passing an oxidizing gas, for example, an oxygen gas. A hole 22d for passing the fuel gas, a hole 22e for passing the cooling water, and a hole 22f for passing the oxidizing gas are provided below the electrolyte membrane 22. On both sides of the electrolyte membrane 22, holes forming circulation passages 29 a and 29 b for circulating cooling water (cooling medium) used for cooling the power generation function unit 28 along the outside of the power generation function unit 28. Parts 23a to 23c and 23d to 23f are formed.
[0010]
A first gasket 30 and a second gasket 32 are provided on both sides of the power generation function unit 28 thus configured. As shown in FIG. 4, the first gasket 30 has a large opening 34 for accommodating the cathode-side electrode 24, while the second gasket 32 has an opening 36 for accommodating the anode-side electrode 26. Is defined. Like the electrolyte membrane 22, the first gasket 30 has holes 30a and 30d for passing fuel gas, holes 30b and 30e for passing cooling water, and holes for passing oxidizing gas. 30c and 30f are provided on the upper side and the lower side, respectively. On both sides of the first gasket 30, holes 31 a to 31 c and 31 d to 31 f forming the circulation passages 29 a and 29 b are formed, and the second gasket 32 has the same configuration as the first gasket 30. Is done.
[0011]
The fuel cell 20 is sandwiched between separators 40. As shown in FIG. 2, the separator 40 is a separator sandwiched between a first manifold plate 42 and a first surface pressure generating plate 44 and a second surface pressure generating plate 46 which are in contact with the first manifold plate 42. It comprises a main body 48 and a second manifold plate 50 abutting on the second surface pressure generating plate 46.
[0012]
As shown in FIG. 5, the first manifold plate 42 is formed of a rectangular flat plate, and is provided with a fuel gas supply concave portion 42a for supplying a fuel gas at an upper right corner thereof. A cooling water discharge hole 42b for discharging the cooling water is provided. An oxidizing gas supply hole 42c for supplying an oxidizing gas is provided at an upper left corner of the first manifold plate 42, and a fuel gas is supplied to a lower left corner of the first manifold plate 42. A fuel gas discharging recess 42d for discharging is provided, and a cooling water supply hole 42e and an oxidizing gas discharging hole 42f are sequentially provided from the fuel gas discharging recess 42d toward the lower right corner. . The fuel gas supply concave portion 42a and the fuel gas discharge concave portion 42d are in communication with each other through an opening 45 for accommodating a fuel gas straightening plate 80 described later. On both sides of the first manifold plate 42, holes 43a to 43c and 43d to 43f forming the circulation passages 29a and 29b are formed.
[0013]
The first manifold plate 42 and the second manifold plate 50 are basically configured symmetrically, as shown in FIG. Although a detailed description of the second manifold plate 50 is omitted, a fuel gas supply hole 50a, a cooling water discharge hole 50b, and an oxidant gas supply recess 50c are provided on the upper side thereof. On the lower side, a fuel gas discharge hole 50d, a cooling water supply hole 50e, and an oxidant gas discharge recess 50f are provided. The oxidizing gas supply concave portion 50c and the oxidizing gas discharging concave portion 50f are in communication with each other through an opening 52 that accommodates an oxidizing gas straightening plate 82 described later. On both sides of the second manifold plate 50, holes 51a to 51c and 51d to 51f forming the circulation passages 29a and 29b are formed.
[0014]
As shown in FIG. 7, the first surface pressure generating plate 44 abutting on the first manifold plate 42 is integrated with a flat plate made of an electronic conductive material or a fuel gas rectifying plate 80 to be described later, or is made of the same material. The fuel gas supply communication hole 44a communicating with the fuel gas supply recess 42a of the first manifold plate 42 and the cooling water discharge communicating with the cooling water discharge hole 42b are provided on the upper side thereof. Communication hole 44b and a communication hole 44c communicating with the oxidizing gas supply hole 42c. A communication hole 44d communicating with the fuel gas discharge recess 42d of the first manifold plate 42, a communication hole 44e communicating with the cooling water supply hole 42e, and an oxidizing agent are provided below the first surface pressure generating plate 44. A communication hole 44f communicating with the gas discharge hole 42f is provided. On both sides of the first surface pressure generating plate 44, holes 57a to 57c, 57d to 57f communicating with the holes 43a to 43c, 43d to 43f of the first manifold plate 42 are formed. The second surface pressure generating plate 46 has substantially the same configuration as the first surface pressure generating plate 44, and a detailed description thereof will be omitted.
[0015]
The separator body 48, which is the third manifold plate, is for supplying cooling water from below to above to cool the power generation function unit 28. As shown in FIG. 8, the relatively thick separator body 48 is preferably made of a conductive dense material (solid body), the fuel gas supply recess 42 a of the first manifold plate 42, and the first surface pressure generation plate 44. A fuel gas supply hole 48a for supplying the fuel gas by communicating with the communication hole 44a of the fuel cell is provided at the upper right corner thereof. A cooling water discharge hole 42b of the first manifold plate 42 and a cooling water discharge recess 48b communicating with a communication hole 44b of the first surface pressure generating plate 44 are adjacent to the hole 48a. The oxidizing gas supply hole 42c of the first manifold plate 42 and the oxidizing gas supply hole 48c communicating with the communication hole 44c of the first surface pressure generating plate 44 are provided at the upper center and at the upper left corner. Is provided.
[0016]
At the lower left corner of the separator body 48, a fuel gas discharge recess 42d of the first manifold plate 42 and a hole 48d communicating with the communication hole 44d of the first surface pressure generating plate 44 are provided. A cooling water supply recess 48e is provided directly below 48b. At the lower right corner of the separator body 48, an oxidizing gas discharge hole 48f is provided. The concave portion 48b and the concave portion 48e are in communication with each other by an opening 62 which is largely defined. On both sides of the separator main body 48, holes 49a to 43d communicating with the holes 43a to 43c and 43d to 43f of the first manifold plate 42 and the holes 57a to 57c and 57d to 57f of the first surface pressure generating plate 44. 49c, 49d to 49f are formed.
[0017]
Rectifying plates 70 and 72 for cooling water are fitted and fixed to the opening 62 of the separator body 48. When the flow straightening plates 70 and 72 for cooling water are joined, the thickness becomes substantially the same as the thickness of the separator main body 48. In FIG. 2, the cooling water straightening plate 70 has a plurality of parallel grooves 70a extending in the vertical direction. Similarly, the cooling water straightening plate 72 has a plurality of parallel grooves 72a. ing. When these cooling water straightening plates 70, 72 are combined, the grooves 70a, 72a respectively define large cooling water straightening passages (cooling passages), and the respective cooling water straightening passages are formed by the cooling water straightening passages. The state of communication with the water discharge recess 48b and the cooling water supply recess 48e is ensured.
[0018]
As shown in FIG. 2, a fuel gas rectifying plate 80 is fitted into the opening 45 of the first manifold plate 42. One surface of the fuel gas baffle 80 is flat, and the other surface is formed with a plurality of parallel grooves 80a extending in the vertical direction. The parallel groove 80a connects the fuel gas supply recess 42a and the fuel gas discharge recess 42d.
[0019]
An oxidizing gas straightening plate 82 is fitted into the opening 52 of the second manifold plate 50. One surface of the oxidizing gas gas flow regulating plate 82 is flat, and the other surface defines a plurality of parallel grooves 82a extending in the vertical direction. The parallel groove 82a connects the oxidant gas supply recess 50c and the oxidant gas discharge recess 50f. Note that the thickness of the first manifold plate 42 and the rectifying plate 80 and the thickness of the second manifold plate 50 and the rectifying plate 82 are substantially the same.
[0020]
The separator body 48 thus configured is sandwiched between the first surface pressure generating plate 44 and the second surface pressure generating plate 46, and these are further sandwiched between the first manifold plate 42 and the second manifold plate 50. The second gasket 32 abuts on the first manifold plate 42, the first gasket 30 abuts on the second manifold plate 50, and the power generation function unit 28 is sandwiched between the gaskets 30 and 32.
[0021]
Explaining in the direction of the arrow shown in FIG. 2, the first manifold plate 42 incorporating the current plate 80, the second gasket 32, the anode 26, the electrolyte membrane 22, the cathode 24, the first gasket 30, the current plate A large number of these sets are laminated, such as a second manifold plate 50 incorporating the 82, a second surface pressure generating plate 46, a separator body 48 incorporating the rectifying plates 70 and 72, and a first surface pressure generating plate 44. The laminated end portion is brought into contact with the first end plate 84, and the other laminated end portion is brought into contact with the second end plate 86, and the first and second end plates 84 and 86 are tightened with stud bolts 87. (See FIG. 1).
[0022]
The first end plate 84 is formed with a groove 84a facing the cooling water discharge hole 42b of the first manifold plate 42 and for diverting the cooling water to the left and right, and both ends of the groove 84a are formed as described above. It faces the holes 43a and 43d of the first manifold plate 42. On both sides of the first end plate 84, grooves 84b and 84c for communicating the holes 43b and 43c and the holes 43e and 43f of the first manifold plate 42 are provided. In the first end plate 84, a through hole 84d for introducing the oxidizing gas and a through hole 84e for discharging the oxidizing gas are further formed.
[0023]
The second end plate 86 has a through hole 86a communicating with the fuel gas supply hole 50a of the second manifold plate 50 to supply the fuel gas, and a through hole 86b communicating with the cooling water supply hole 50e. Thus, a through hole 86c communicating with the fuel gas discharge hole 50d and through holes 86d and 86e communicating with the holes 51c and 51f are formed (see FIG. 2). On the inner surface of the second end plate 86 facing the second manifold plate 50, grooves 88a and 88b for communicating the holes 51a and 51b and the holes 51d and 51e of the second manifold plate 50 are provided.
[0024]
The operation of the fuel cell 10 configured as described above will be described.
[0025]
First, the plurality of fuel cells 20 are sandwiched between the separators 40, stacked so that the respective communication holes, holes and recesses communicate with each other, and fixed by the first and second end plates 84 and 86.
[0026]
Then, when the fuel gas (hydrogen gas) is supplied to the fuel cell 10 from the through hole 86a of the second end plate 86, the fuel gas is supplied from the fuel gas supply hole 50a of the second manifold plate 50 to the first manifold. The power generation function section 28 is supplied to the fuel gas supply concave portion 42a of the plate 42 and is provided through the groove 80a of the fuel gas straightening plate 80 provided in the opening 45 communicating with the fuel gas supply concave portion 42a. It is supplied to the anode 26.
[0027]
On the other hand, the oxidizing gas (air) is supplied to the fuel cell 10 through the through hole 84 d of the first end plate 84, and the oxidizing gas supply hole 42 c of the first manifold plate 42 and the oxidizing gas supply It reaches the oxidant gas supply concave portion 50c of the second manifold plate 50 through the hole 48c. The oxidizing gas is supplied to the cathode 24 from the oxidizing gas supply recess 50c through the groove 82a of the oxidizing gas straightening plate 82.
[0028]
The unused fuel gas is discharged to the outside from the through hole 86c of the second end plate 86 via the fuel gas discharge recess 42d of the first manifold plate 42, and the unused oxidant gas is discharged to the second manifold 86. The gas is discharged to the outside from the through hole 84e of the first end plate 84 via the oxidant gas discharge recess 50f of the manifold plate 50 and the like.
[0029]
The cooling water is supplied into the fuel cell 10 from the through hole 86b of the second end plate 86, and the cooling water supply recess of the separator main body 48 via the cooling water supply hole 50e of the second manifold plate 50 and the like. 48e. The cooling water flows upward along the cooling water straightening passage defined between the cooling water straightening plates 70 and 72 fitted and fixed to the opening 62 of the separator main body 48, and the power generation function unit 28 After cooling the power generation function section 28 by absorbing the heat generated in the first step, the power flows from the cooling water discharge recess 48b of the separator body 48 to the first end plate 84 side.
[0030]
The cooling water used for heat removal of the power generation function unit 28 is discharged from the groove 84 a provided in the first end plate 84 to the outside through the through holes 86 d and 86 e of the second end plate 86 through the circulation passages 29 a and 29 b. Is done. That is, the cooling water introduced into the groove 84a of the first end plate 84 is diverted to the left and right along the groove 84a, and flows into the holes 43a and 43d of the first manifold plate 42 forming the circulation passages 29a and 29b, respectively. Supplied.
[0031]
The cooling water supplied to the hole 43a of the first manifold plate 42 reaches the groove 88a of the second end plate 86 via the hole 49a of the separator body 48, the hole 51a of the second manifold plate 50, and the like. The cooling water is supplied to the groove 84b of the first end plate 84 via the hole 51b of the second manifold plate 50, the hole 49b of the separator main body 48, the hole 43b of the first manifold plate 42, and the like communicating with the groove 88a. be introduced. For this reason, the cooling water further flows from the groove 84b through the hole 43c of the first manifold plate 42, the hole 49c of the separator main body 48, the hole 51c of the second manifold plate 50, and the like. 86d is discharged outside.
[0032]
On the other hand, the cooling water supplied from the groove portion 84a of the first end plate 84 to the circulation passage 29b similarly causes the holes 43d, 49d, and 51d in the first manifold plate 42, the separator body 48, and the second manifold plate 50. After reaching the groove 88b of the second end plate 86 via the holes 51e, 49e and 43e, it is returned to the groove 84c of the first end plate 84. Further, the cooling water is discharged to the outside from the through hole 86e of the second end plate 86 via the holes 43f, 49f, and 51f communicating with the groove 84c (see FIG. 1).
[0033]
As described above, in the present embodiment, the cooling water supplied to the fuel cell 10 and removing the heat of the power generation function unit 28 is circulated on both sides of the power generation function unit 28 along the circulation passages 29a and 29b. . For this reason, on both sides of the power generation function unit 28, the cooling water whose temperature has been increased due to the heat exchange performed by the power generation function unit 28 flows along the circulation passages 29a and 29b. (See FIG. 9).
[0034]
Thereby, the temperature difference between the central portion of the power generation function portion 28 and the both end portions of the power generation function portion 28 can be made as small as possible, and the both ends of the power generation function portion 28 are condensed due to the temperature drop. Can be reliably prevented from occurring. Therefore, there is no portion that does not operate due to dew condensation in the power generation function portion 28, and the portion where the performance is deteriorated due to low temperature is reduced. Therefore, an effect is obtained that the effective operating area and the performance of the power generation function unit 28 can be effectively improved.
[0035]
Furthermore, in the present embodiment, only the circulation passages 29a and 29b for circulating the cooling water after the heat exchange along both outer sides of the power generation function unit 28 are provided in the fuel cell 10, and the entire structure of the fuel cell 10 is provided. Can be dealt with easily and economically without any complication.
[0036]
By the way, in the present embodiment, the circulation passages 29a and 29b are configured to pass three times (one reciprocating half) on both sides of the power generation function unit 28, respectively. However, the circulation passages 90a and 90b shown in FIG. You may. The elongated holes 92a and 92b forming the circuit passages 90a and 90b are formed to be long in the vertical direction with respect to both side portions of the second manifold plate 50. Although not shown, both sides of the first manifold plate 42, the second gasket 32, the electrolyte membrane 22, the first gasket 30, the second surface pressure generating plate 46, the separator body 48 and the first surface pressure generating plate 44 Elongated long holes communicate with each other in the vertical direction.
[0037]
In the circulation passages 90a and 90b configured as described above, the cooling water used for heat removal of the power generation function unit 28 and sent to the first end plate 84 side is provided with vertically long holes 92a and 92b and the like. After passing through the cooling water, the cooling water is discharged to the outside. Therefore, the temperature of both sides of the power generation function unit 28 can be integrally adjusted in the vertical direction, and the same effects as those of the above-described circulation passages 29a and 29b can be obtained.
[0038]
【The invention's effect】
In the fuel cell according to the present invention, a relatively high-temperature cooling medium heat-exchanged in the power generation function unit is circulated along the outside of the power generation function unit, so that a partial temperature difference is generated in the power generation function unit. No cause. As a result, the occurrence of dew condensation can be prevented, and the effective operating area and performance of the power generation function unit can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic perspective explanatory view of a fuel cell according to the present invention.
FIG. 2 is a partially omitted exploded perspective view of the fuel cell.
FIG. 3 is a front view of a power generation function unit constituting the fuel cell.
FIG. 4 is an explanatory front view of a gasket constituting the fuel cell.
FIG. 5 is an explanatory front view of a manifold plate constituting the fuel cell.
FIG. 6 is an explanatory front view of a manifold plate constituting the fuel cell.
FIG. 7 is an explanatory front view of a surface pressure generating plate constituting the fuel cell.
FIG. 8 is an explanatory front view of a separator main body constituting the fuel cell.
FIG. 9 is an explanatory diagram of a temperature in a lateral direction of the power generation function unit constituting the fuel cell.
FIG. 10 is a partially omitted perspective view of a fuel cell illustrating another configuration of a circuit passage.
FIG. 11 is an explanatory diagram of a temperature in a lateral direction of a power generation function unit according to the related art.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Fuel cell 20 ... Fuel cell 22 ... Solid polymer electrolyte membranes 23a-23f, 31a-31f, 43a-43f, 49a-49f, 51a-51f, 57a-57f ... Hole 24 ... Cathode side electrode 26 ... Anode Side electrode 28 Power generation function 29a, 29b, 90a, 90b Circulating passage 30, 32 Gasket 40 Separator 42, 50 Manifold plate 44, 46 Surface pressure generating plate 48 Separator body 70, 72 Rectification of cooling water Plates 84, 86: End plates 84a to 84c, 88a, 88b: Grooves 92a, 92b: Slots

Claims (9)

Comprising a fuel cell structure constituted by sandwiching a solid polymer electrolyte membrane between the anode electrode and a cathode electrode, a laminate laminating a separator sandwiching said fuel cell structure, the end of the laminate A fuel cell sandwiched between plates ,
Inside the fuel cell, a cooling passage for cooling a power generation function unit of the fuel cell structure is provided ,
In the laminate, a cooling medium supply hole and a cooling medium discharge hole communicating with the cooling passage ,
A passage wherein the cooling medium used coolant communicated to discharge hole for cooling the power generation function unit, Kai cruiser that is cyclically along the outside of the power-generating function unit,
Is formed through the fuel cell. 2. The fuel cell according to claim 1, wherein the fuel cell structures are stacked in a horizontal direction, and the cooling passage supplies the liquid cooling medium as the cooling medium to the power generation function unit in a vertical direction. 3. Is configured as
The cyclic passage, a fuel cell for causing cyclically the liquid cooling medium in the horizontal direction along the outer sides of the electric generation section. 3. The fuel cell according to claim 1, wherein the circulation passage reciprocates the cooling medium at least once along both outer sides of the power generation function unit. 4. The fuel cell according to any one of claims 1 to 3, at least one the previous SL end plate, wherein the said cooling medium of spent flowing through the cooling passage grooves for supplying to said cyclic path A fuel cell, which is provided. 2. The fuel cell according to claim 1, wherein the power generation function units are stacked in a horizontal direction.
A gas supply hole provided on the upper side of the power generation function unit for supplying at least a reaction gas that is either a fuel gas or an oxidant gas; and a gas supply hole portion for discharging the reaction gas. A gas exhaust hole provided on the lower side,
The cooling passage allows the cooling medium to flow from the lower side to the upper side with respect to the power generation function unit,
The fuel cell according to claim 1, wherein the circulation passage causes the cooling medium to flow to the left and right sides with respect to the power generation function unit. Comprising a fuel cell structure constituted by sandwiching a solid polymer electrolyte membrane between the anode electrode and a cathode electrode, a laminate laminating a separator sandwiching said fuel cell structure, the end of the laminate A fuel cell sandwiched between plates ,
Inside the fuel cell, a cooling passage for cooling a power generation function unit of the fuel cell structure is provided ,
In the laminate, a cooling medium supply hole and a cooling medium discharge hole communicating with the cooling passage ,
A cyclic path the cooling communicated to the medium discharge hole cooling medium used for cooling of the electric generation section, is circulated along the outer side of the power-generating function unit,
Is formed through ,
The circulation passage extends in a direction intersecting with a direction in which the cooling medium flows and in parallel with a side portion of the power generation function section, in order to allow the cooling medium to pass in one direction along the outside of the power generation function section. A fuel cell characterized by including an existing slot. 7. The fuel cell according to claim 6, wherein the cooling passage is configured to supply the cooling medium to the power generation function unit in a vertical direction.
The fuel cell, wherein the circulation passage circulates the cooling medium in a horizontal direction along both outer sides of the power generation function unit. 8. The fuel cell according to claim 6, wherein the circulation passage reciprocates the cooling medium at least once along both outer sides of the power generation function unit. The fuel cell according to any one of claims 6 to 8, further comprising a pair of end plates disposed at both ends of the fuel cell,
A fuel cell, wherein at least one of the end plates is provided with a groove for supplying the used cooling medium flowing through the cooling passage to the circuit passage.

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